In a MBMS (Multimedia Broadcast Multicast Service) system, 3GPP (Third Generation Partner Project) has agreed multi-cell MBSFN (MBMS Single Frequency Network) transmission of MCCH. Thus, a mechanism is needed to ensure the MCCH synchronization. Parameters such as MSAP (MBMS Subframe Allocation Pattern) allocated by a MCE (MBMS Control Entity) should be synchronized at different eNBs (base stations) for the sake of user plane content synchronization.
There is an existing proposal in 3GPP RAN3 (Radio Access Network, task group 3), wherein a new AMBR (Aggregate Maximum Bit Rate) to the eNB is needed to be activated simultaneously, so that all the eNBs can make a scheduling according to the new AMBR at the same time. This can be done by a simple mechanism wherein a time stamp indicating for example the next scheduling interval is carried inside a Session Update message. Such a procedure is also needed when there is change for a single service carried on a GBR (Guaranteed Bit Rate) bearer.
However, there are the following defects in the above proposal.                1) In the above proposal, only the Session Update message is mentioned. However, there are a lot of other messages over M2 and M3 interfaces.        2) The proposal is based on a time stamp, e.g. scheduling period, which relates to a user plane idea, different from controlling information element in the invention as described hereinafter. On the other hand, the scheduling period may not be suitable for a GW (gateway) because the GW does not know the scheduling information.        3) There is no description about how eNB responds to the activation time information in the above proposal.        4) How to set the activation time information is not mentioned in the above proposal.        